KR100339748B1 - Vehicle glass antenna and design method - Google Patents

Abstract

(Objective) We propose a high-performance vehicle glass antenna by combining antenna lines installed on two glass surfaces of a vehicle.

(Configuration) The first antenna wire 20 extending on the first glass 10L to receive the FM radio wave, and having the feed point 16 formed on the glass, and the feed point 16 to receive the AM radio wave. The second antenna wire 30 connected to the first antenna wire 20 in the vicinity, the third antenna wire 31 extending on the second glass 10R to receive AM radio waves, and the second antenna wire An AV connection line for connecting the 30 and the third antenna wire 31 is provided.

Description

Vehicle glass antenna and design method

The present invention relates to a glass antenna for a vehicle having a special back glass such as a van and a design method thereof.

In general, as a vehicle antenna, a pole antenna that protrudes and feeds a pole (rod) on its body in an insulated state is widely known. However, this pole antenna is easy to cause the pole to bend or break, and also to wind during driving. Since there is a problem that a splitting sound is generated, glass antenna has been put into practical use as an alternative antenna. This glass antenna is usually installed in the rear window glass in consideration of appearance.

However, in vans or so-called hatchback cars, it is often difficult to secure a large rear glass area. In addition, in order to open and close the rear door, it is necessary to devise a device that is easy to bend, such as an antenna feeder line, which may cause a cost increase.

If you install an antenna on a small window pane,

①: If the antenna is an FM antenna, the required antenna length cannot be obtained.

②: If the antenna is an FM antenna, it cannot take large impedance.

③: If the antenna is an AM antenna, reception sensitivity is lowered.

④: Because it is necessary to install near vehicle harness, it is easy to receive noise from harness.

Has a problem. In the case where the antenna sensitivity is low, it is conceivable to increase the signal level by adding a heavy amplifier, but it is not meaningful because the noise component increases.

In order to increase or adjust the reception sensitivity, various proposals have been made in the past.

For example, Japanese Patent Laid-Open No. 4-77005 arranges antenna lines on two opposing side glass surfaces, and combines the respective reception outputs.

However, in this method, since the signal line for synthesizing the antenna conductor output provided on each glass surface functions as a new antenna conductor, it is often difficult to obtain the original object. Therefore, in Japanese Patent Laid-Open No. 4-77005, a wide area cut coil is formed or a phase adjusting conductor element is provided.

In addition, as in Japanese Patent Application Laid-Open No. 1-292902, it is also proposed to have a main antenna extending vertically downward as a feed point at the center of the upper side of the window glass and an antenna for impedance adjustment connected to the main antenna near the feed point. have.

In this prior art, the impedance adjusting antenna actually functions as an antenna for impedance adjustment, and the antenna itself does not contribute to reception to increase reception sensitivity.

The two prior arts are characterized in that some other element is mounted on the glass antenna, and therefore, these are factors of cost increase.

The present invention has been made in view of the above, and an object of the present invention is to propose a glass antenna for a vehicle that realizes high-performance frequency diversity by combining antenna lines respectively provided on two glass surfaces of a vehicle.

Another object of the present invention is to propose a method for easily designing a high performance frequency diversity antenna system.

Another object of the present invention is to propose a high-performance vehicle glass antenna which eliminates the need for a portion that does not directly contribute to the improvement of reception sensitivity.

In order to achieve the above object, the vehicle glass antenna which has received the radio wave of the first frequency band of the first invention of the present invention and the second frequency band lower than the first frequency band, is made to receive the radio wave of the first frequency band. A first antenna line extending over the glass, having a feed point formed on the glass, and extending over the first glass to receive radio waves of the second frequency band, and extending to the first antenna line near the feed point; A second antenna wire to be connected, a third antenna wire extending on the second glass and another glass to receive radio waves of the second frequency band, and a connection wire for connecting the second antenna wire and the third antenna wire As an end, one end is connected to the third antenna wire at a predetermined first connection position on the second glass, and the other end is on the first glass surface. And a connection line connected to the second antenna line at a predetermined second connection position spaced apart from the feed point.

According to such a configuration, the second antenna wire is an antenna line for receiving radio waves of the second frequency and also functions as a stub for the first antenna wire. The third antenna line is connected to the feed point via the connecting line and the second antenna line. This stub structure and the second antenna line and the third antenna line in series can eliminate the influence of the AM receiving antenna line on the FM reception, and as a result, can provide a high-performance frequency diversity antenna system. And the coil and adjustment antenna wire which were conventionally needed can be made unnecessary.

The glass antenna of the second invention of the present invention is a glass antenna for a vehicle which receives radio waves of a first frequency band and a radio wave theory of a second frequency band lower than the first frequency band, and is provided on the side of the vehicle to receive the radio waves of the first frequency band. A first antenna line extending over the glass and having a feeding point formed on the glass, and extending along a circumferential edge of the first glass to receive radio waves of the second frequency band, one end of which is located near the feeding point; A second antenna wire connected to the first antenna wire, a third antenna wire extending on the second glass on the side opposite to the first glass in the left and right direction with respect to the first glass to receive radio waves of the second frequency band; And a connecting line for connecting the second antenna wire and the third antenna wire, one end of which is formed on the second glass. According to the position connected to said third antenna line, characterized by comprising a connection line connected line and the second antenna in a position separate from the other end from the first the feeding point on the first glass surface.

By actively using the two side glasses on the left and right, and by the same function as the glass antenna of the first invention, high frequency diversity can be achieved.

According to the third invention, the feed point of the first antenna line is formed on the circumferential edge of the first glass surface.

According to a fourth invention, the first frequency band is an FM frequency band, and the second frequency band is an AM frequency band.

According to a fifth aspect of the invention, the first antenna line extends downward at an approximately center position in the width direction of the first glass surface. It is preferable that the first antenna wire for receiving radio waves of high frequency is provided to extend at a position other than the edge of the glass.

According to a sixth aspect of the present invention, the second antenna line is one line extending along a horizontal edge portion and a substantially vertical edge portion of the first glass surface. By using the glass surface to the maximum, as long as possible to secure the antenna wire, the antenna wire has fewer invalid antenna wire portions extending inwardly of the glass.

According to a seventh aspect of the present invention, the second antenna wire is not closed by being installed to extend along the circumferential edge of the first glass surface and to terminate the end point thereof.

According to the eighth invention, the second antenna wire is provided along the circumferential edge of the first glass surface, and has branch lines near the end thereof. You can actively use the empty area of the glass surface.

According to a ninth aspect of the invention, the third antenna line is a branch line extending along a substantially horizontal circumferential edge above the second glass, and at least two branches extending along a circumferential edge of the second glass in a substantially vertical direction. It is characterized by having a line. The effect of harness noise can be reduced by having one branch line extending horizontally.

According to a tenth aspect of the present invention, the first glass and the second glass have a substantially rectangular shape, and the second antenna line has branch lines extending along a substantially horizontal circumferential edge below the first glass. The three antenna lines have branch lines extending along a substantially horizontal circumferential edge of the lower portion of the second glass, and the distance from the lower end of the second glass to the branch lines of the third antenna line is equal to that of the first glass. It is set longer than the distance from the lower end to the branch line of the second antenna line.

The effect of the harness noise can be reduced by keeping the antenna wire on the second glass away from the harness.

According to the eleventh invention, the branch line of the third antenna line, which extends along the substantially horizontal circumferential edge of the second glass, begins to extend from the upper circumferential edge of the second glass, It is characterized by terminating at a position shorter than the vertical length of two glasses.

The influence of the harness noise can be loaded by keeping the antenna wire on the second glass away from the harness and by not extending the antenna wire on the bottom side.

According to a twelfth invention, the connection line is an AV line. By using an AV line, the above serial connection effect can be enhanced.

In order to receive the radio wave of the 1st frequency band of this invention and the 2nd frequency band lower than the said 1st frequency band in order to achieve the said subject, the antenna line is designed to extend and install on the 1st glass surface and the 2nd glass surface of a vehicle. The method of claim 1, wherein the length of the first antenna wire and the position of the feed point, which extend substantially in the vertical direction on the first glass for receiving the radio waves of the first frequency band, are determined, and the position of the first feed point is determined from the feed point position. Determine the length and the termination position of the second antenna wire extending along the circumferential edge of the upper surface of the glass surface, and the second antenna wire is connected to the second antenna wire by the connecting line opened from the termination position of the second antenna wire. The length of the third antenna wire electrically connected to the antenna line, and the impedance of the second antenna wire and the third antenna wire are the first It is characterized in that the decision to display a high value for the frequency band.

The antenna can be designed simply without considering the mutual influence between the first antenna line and the second and third antenna lines.

Hereinafter, two preferred embodiments of the present invention will be described with reference to the accompanying drawings.

Both embodiments are common in that both FM and AM radio waves are received with high sensitivity, and the first embodiment is provided with an FM glass antenna and an AM glass antenna in one side glass of a vehicle. An example is the installation of an FM glass antenna and an AM glass antenna on one side glass, and an additional AM antenna on a side glass facing each other. Since the side glass of a vehicle (rear glass) is made upright compared with the front glass, the length of a vertical glass cannot be taken large. Both embodiments solve this problem of side glass.

<First Embodiment>

Configuration of the First Embodiment

1 illustrates an embodiment in which the glass antenna of the present invention is applied to the left side glass of an automobile.

In the same figure, 10L is the left side glass of an automobile (illustration of the main body of the vehicle is omitted). Here, the inner direction of FIG. 1 is the rear of the vehicle, and the immediately forward direction is the front of the vehicle. In addition, when the passenger boards, the glass on the right toward the front is right side glass (10R (not shown in FIG. 1)), and the glass on the left side is left side glass (10L).

In Fig. 1, (20 (20-1, 20-2)) is mainly an FM radio reception antenna line, (20-1) is a main antenna line, and (20-2) is a vehicle that this vehicle should receive. It is an additional part added to suit the length of the antenna line 20 so as to receive the frequency band of the FM radio waves with sensitivity. The antenna line 20 is a so-called monopole antenna in this embodiment, and extends downward from the feed point 16 as shown in FIG. The additional antenna line 20-2 is bent relative to the main antenna line 20-1 because the length required for the antenna line 20 exceeds the length of the upper and lower directions of the glass 10L of FIG.

1, the signal line 13 of the coaxial cable 12 is connected to the feed point 16. In FIG. The cable 12 is connected to a TV device, an FM tuner, or an AM tuner, not shown.

The antenna wire 30 is further extended on the glass 10L. The antenna line 30 is connected to the antenna line 20 at the feed point 16 and extends along the circumferential edge of the glass 10L starting from the feed point 16. The antenna line 20 mainly receives FM radio waves, but the antenna line 30 functions to receive AM radio waves together with the antenna line 20. In other words, if the main antenna portion of the antenna line 30 is 30-1, the main antenna line 30-1 extends toward the rear of the vehicle, and the additional antenna line 30-2 is provided. It is connected to the terminal part of the main antenna wire 30-1, and is installed extending substantially downward from this terminal part, and the additional antenna wire 30-3 is connected to the terminal part of the additional antenna wire 30-2. Connected to and extends substantially forward from this terminal, and an additional antenna wire 30-4 is connected to the terminal of the additional antenna wire 30-3 and is installed to extend substantially upward from this terminal. In addition, the additional antenna wire 30-5 is connected to the terminal portion of the additional antenna wire 30-4 and extends from the terminal portion toward the rear.

In the example of FIG. 1, when the length in the horizontal direction of the glass is about 920 mm, and the length in the horizontal direction of the bottom is about 880 mm, the length of the FM receiving antenna line 20-1 is about 370 mm. The length of the line 30-4 was set to about 370 mm, and the length of the branch line 30-5 was set to about 450 mm. In this way, the total length of the antenna wire 30 became 2300 mm. The antenna wires 30-1 and 30-5 are about 50 mm from the edges of the glass edges, and the antenna wires 30-2 are about 35 mm from the edges of the glass edges. Silver was set to about 30 mm from the edge of the edge of the glass. The antenna branch line 20-2 is spaced apart from the antenna line 30-3 by a distance of 10 mm. Moreover, according to various experiments, the antenna line 30 provided in the outer periphery was good if it was in the range of about 10 mm-30 mm from the periphery of the glass (namely, the vehicle body back surface).

Principle of the first embodiment

In the first embodiment, the antenna line 20 is mainly used for FM reception. On the other hand, for the AM frequency band, the antenna line 20 and the antenna line 30 act as antenna conductors. That is, the antenna lines 20-1 and 20-2 constitute an FM antenna, and the antenna lines 20-1, 20-2 and the antenna lines 30-1, 30-2 and 30-30. 3) Both 30-4 and 30-5 constitute AM antennas.

The principle of the AM / FM antenna system of the first embodiment has a feed point at the circumferential edge of the window glass, from which the antenna line 20 is installed as a monopole antenna in the vertical direction and the main antenna of the antenna line 20 It extends from the part 20-1 and in turn until the desired length is obtained so that the AM antenna lines 20 and 30 are not spaced apart along the periphery of the glass 10L and from the periphery. .

Since the antenna line 20 for receiving FM radio waves having a high frequency can be set shorter than the AM antenna lines 20 and 30, the monopole antenna can be configured. In order to form a high performance antenna system by the antenna line 20 and the antenna line 30, it is preferable that the AM antenna lines 20 and 30 do not affect the reception of the FM antenna line 20 FM radio waves. However, the monopole antenna antenna line 20 is relatively short because it is provided on the side glass of the vehicle. Therefore, the impedance of the antenna line 20 itself cannot be lowered (about 10 Ω) and is easily affected by the AM antenna lines 20 and 30. Therefore, in the first embodiment, the impedance is increased by extending a portion 30 of the AM antenna wire along the circumferential edge of the glass.

2 to 6 are diagrams when the length of the antenna wire 30 is increased. As shown in FIG. 2, when the reception sensitivity of the AM radio wave only when the antenna line 20 is used (0 dB) is set, the AM line 30-1 is increased by 3 dB by adding ON (see FIG. 3) and the AM line 30 -2) by adding (30-3) (see FIG. 4) to increase 1.9 dB, and by adding (+5) AM line (30-4) to 2.2 dB, and by AM line (30-5) ), It can be seen that it is increased by 1.5 dB (see Fig. 6). That is, with the antenna line of the structure of FIG. 1, the total reception sensitivity of 8.6 dB was increased compared with the antenna system of FIG.

Improvement of AM reception sensitivity

7 is a diagram showing an increase in an additional line for the purpose of further increasing the reception sensitivity of AM radio waves. In other words, the branch line 30-5 extends closer to the antenna line 20 and affects the sensitivity of the FM antenna. Thus, as shown in FIG. 7 in parallel to the antenna line 20, branch lines 30-6 of AM antenna lines are added. The branch line of the antenna line 30 should originally be installed along the circumferential edge of the glass. However, when the branch line is separated from the circumferential edge of the glass surface as shown in FIG. The rate of increase is reduced. In addition, in the example of FIG. 7, the addition of the branch lines 30-6 increased the 0.6 dB sensitivity. In order to further increase the AM reception sensitivity, a branch line parallel to the branch line 30-6 may be added.

In addition, the position of the AM antenna branch line 30-6 does not obstruct the passenger's watch, and it is not necessary to be in the middle of the antenna branch line 30-4 and the antenna line 20-1. It can be installed in

Incidentally, increasing the AM reception sensitivity by adding the AM branch lines 30-6 can also be applied to the antenna system of the second embodiment described later.

Breakage Measures for Antenna Lines

The side glass of an automobile is often rubbed by passengers or the like by cleaning the surface on which the antenna line extends. Therefore, the probability that the antenna line 20 which is important as an FM receiving antenna will break is high. 8 shows dashed countermeasures.

8, branch line 20-3, branch line 20-4, branch line 20-5 are added to FM antenna line 20-2, and branch line 20- is added. The end of 5) is connected to the feed point 16. In this way, the FM antenna line 20-1, the branch line 20-2, the branch line 20-3, the branch line 20-4, and the branch line 20-5 form one loop. . In other words, the FM antenna lines are redundant. For this reason, even if there is a broken line at any one place, the FM antenna wire after being cut functions as two monopole antennas, and the FM receiving function is maintained.

Moreover, the FM antenna to the redundant line have a similar function to those shown in the Figure 8 the various spacing, has a _{d 1 = d 2 = d 3} = 10mm.

FIG. 9 shows the case where the break occurs in the branch line 20-5 (that is, the break occurs in the middle of the antenna line), and FIG. 10 shows the case where the break occurs in the branch line 20-3 (that is, the tip of the antenna line). Break occurs).

The solid line I in Figs. 11 and 12 shows the reception sensitivity of the horizontal polarized wave and the reception sensitivity of the vertical polarized wave, respectively, when there is no break. The broken lines II in FIGS. 11 and 12 indicate the reception sensitivity of the horizontally polarized wave and the reception sensitivity of the vertically polarized wave in the case where the breakage as shown in FIG. 9 occurs, respectively. Even if breakage occurs, it is understood that the sensitivity deterioration caused by the difference in auditory sense does not occur. The solid line I in FIG. 13 and FIG. 14 shows the directivity characteristic with respect to the horizontal polarization and the vertical polarization, respectively, when there is no break. The broken lines II in FIGS. 13 and 14 indicate the directing characteristics for the horizontal polarization and the vertical polarization in the case where breakage as in FIG. 9 occurs, respectively. It is understood that even if breakage occurs, deterioration of directivity does not occur.

The solid line I in Figs. 17 and 18 shows the reception sensitivity of the horizontally polarized wave and the reception sensitivity of the vertically polarized wave, respectively, when there is no break. The broken lines II in Figs. 17 and 18 show the reception sensitivity of the horizontal polarized wave and the reception sensitivity of the vertical polarized wave, respectively, when a break like that in Fig. 10 occurs at the distal end. Even if breakage occurs, it is understood that the sensitivity deterioration caused by the difference in auditory sense does not occur. The solid lines I in Figs. 15 and 16 show the directing characteristics with respect to the horizontally polarized wave and the vertically polarized wave when there is no break. The broken lines II in FIGS. 15 and 16 show the directing characteristics for the horizontal polarization and the vertical polarization in the case where a break such as that in FIG. 10 occurs. It is understood that even if breakage occurs, deterioration of directivity does not occur.

The above measures for breaking the antenna line can also be applied to the antenna system of the second embodiment described later.

<Effect of First Embodiment>

According to the antenna system of the first embodiment described above,

(1): Despite the limitation of the side glass that the area cannot be large, by folding back the antenna wires in sequence (for example, the antenna wires 20-1 and 20-2, or the antenna wire 30-1) The length of the required FM antenna wire is secured.

②: Despite the limitation of the side glass that cannot take a large area, that is, the limitation of the impedance of the FM antenna wire, the antenna wire 30-1 functions as an open stub for the FM receiving antenna wire 20. Therefore, the AM antenna branch line 30 does not affect the antenna line 20. That is, the antenna system can be configured so that each does not affect the reception performance of the other.

(3) Since the antenna wire 30 extends along the edge of the glass, sufficient reception sensitivity can be ensured for AM reception.

④: A long antenna line must be secured for AM reception, and conventionally, only an antenna line can be provided on a large rear glass, and a defogger on the rear glass can be used to increase the sensitivity. There was only active use. However, as described above, the side glass has a small area and no wiring is formed in the defogger. In the first embodiment of the present invention, the AM antenna line is arranged at the edge of the window glass, and thus sufficient reception sensitivity is obtained, thereby eliminating the need for a defogger (which is necessary when using a defogger). No need for choke coils), and the overall configuration was simplified.

Second Embodiment

The second embodiment described next is an embodiment in which the AM reception sensitivity is further improved. This second embodiment is characterized in that an AM antenna line extends over two glass surfaces.

Configuration

19 illustrates the configuration of the antenna system of the second embodiment. In the same drawing, the glass 10L shows the left side glass as in the first embodiment, and the 10R shows the right side glass provided against the left side glass 10L against each other. For the sake of illustration, the shapes of the glass 10L and 10R are shown in FIG. 19 in the form of rectangles. However, the glass 10L and 10R may be in the shape of parallelograms as in the first embodiment as in FIG. 20, or may have any shape. do.

On the surface of the right side glass 10R of FIG. 19, the additional antenna line 31-1 for AM reception, the additional antenna line 31-2, the additional antenna line 31-3, and the additional antenna line 31-4. An additional antenna line 31-5 is provided. The AM antenna wire 30 provided on the left side glass 10L and the AM antenna wire 31 provided on the right side glass 10R are connected by the connected (14). The connecting line 14 is connected to the connection point 15R with the AM antenna line 31 provided with the right side glass 10R at the connection point 15L with the AM antenna line 30 provided with the left side glass 10L. Is connected. That is, in the second embodiment, the antenna line 20 is mainly used for FM reception, and for the AM frequency band, the antenna line 20 and the antenna lines 30 and 31 act as antenna conductors. That is, the antenna lines 20-1 and 20-2 constitute an FM antenna, and the antenna lines 20-1 and 20-2 and the antenna lines 30-1 and 30-2 and 30-3. (30-4) 30-5 and three sets of antenna lines 31-1, 31-2, 31-3, 31-4, and 31-5 form an AM antenna. .

In FIG. 19, the cables 11L and 11R are cable harnesses normally covered by the vehicle body, which are disposed below the glass 10L and 10R, respectively.

In FIG. 20, the arrangement | positioning of the antenna line 20 and the antenna line 30 extended from the left side glass 10L of FIG. 19 is shown. In FIG. 21, the arrangement | positioning of the AM antenna line 31 extended in the right side glass 10R of FIG. 19 is shown. Comparing the twentieth embodiment of the second embodiment with the first embodiment of the first embodiment, it can be seen that the connection line 14 is connected at the connection point 15L.

Open stub structure

As in the first embodiment described above, the extension of the AM antenna line should not adversely affect reception of FM radio waves. On the other hand, as in the first embodiment, since the area on the left side glass is small, the impedance of the antenna line 20 must be small.

19 and 20, the line between the feed point 16 of the AM antenna line 30-1 and the connection point 15L is used as a stub for achieving impedance matching between the antenna line and the feeder line 13. Works. In order to match the impedance of the antenna line and the feeder line, the stub usually changes the impedance of the antenna line so that the impedance of the antenna line and the feeder line is matched so that the reflected wave does not occur.

In this second embodiment, the connection line for connecting the left glass and the right glass functions as a normal stub by using a normal AV line instead of a coaxial cable or the like and by appropriately setting the position of the connection point 15L. At the same time, it is characterized in that the AM antenna line 30 on the left glass 10L and the AM antenna line 31 on the right glass 10R have a large impedance as viewed from the antenna line 20. . If the antenna wires 30 and 31 have a large impedance as seen from the FM antenna wire 20, the AM antenna wires 30 and 31 become as if they do not exist in the FM antenna wire 20, and the antenna The influence on the line 20 becomes negligible.

22 to 33 show respective FM frequencies when the position of the connection point 15L with the connection line 14 for connecting the antenna line 31 of the right glass is varied on the left glass surface. Display the impedance characteristic for VSWR. In the angular plane, (1) indicates the distance from the feed point 16 of the connection contact 15L, and 1 = 20 cm (FIG. 22) is located at the position indicated by the connection point 15L in FIG. 20. Displays the case, if any. 34 to 44 show the positions of the connection points 15L of the VSWR diagram shown in FIGS. 23 to 33, respectively.

FIG. 45 shows VSWR when the right glass is not present. As can be seen from FIGS. 22 to 33, the VSWR is good in a wide frequency range if the connection point 15L is spaced apart from the feed point 16 by a suitable distance, and the connection point 15L is placed on the circumferential edge of the glass surface. It can be seen that the characteristic is obtained. Also, it can be seen from FIG. 45 that when the AM antenna lines exist on the left and right glass, better VSWR characteristics are obtained than when the AM antenna lines do not exist on the right glass.

Thus, according to the second embodiment, even if the AM antenna line 31 is present in the right glass 10R, the antenna line 31 has a large impedance with respect to the antenna line 20, and the existence thereof is present. Does not affect the reception characteristics of the FM.

46 shows reception sensitivity (solid line) when the horizontally polarized FM radio wave is received by the antenna system (antenna system of FIG. 19) having the open stub structure (structure having AM line 30) of the second embodiment; The reception sensitivity (dashed line) when received by the antenna system (not shown) installed in the pillar is displayed. Similarly, Fig. 47 shows the directivity (solid line) when the horizontally polarized FM radio wave is received by the antenna system of the second embodiment and the directivity (dashed line) when it is received by the filler antenna system. Similarly, FIG. 48 shows the reception sensitivity (solid line) when the vertically polarized FM radio wave is received by the antenna system of the second embodiment and the reception sensitivity (dashed line) when it is received by the filler antenna system. 46 to 48 show that FM radio wave reception performance of the antenna system having the stub structure of the second embodiment is inferior to that of the filler antenna.

49 shows reception sensitivity characteristics (solid line) when the horizontally polarized FM radio waves (76 MHz to 90 MHz) are received by the antenna system having the stub structure (structure having the branch line 30 for AM) of the second embodiment. Reception sensitivity when the antenna system does not have the stub structure (not shown in FIG. 20, but does not have the AM antenna line 30, but only the antenna line 20 in the antenna system). Is displayed. 50 is a diagram comparing the antenna system (solid line) of the second embodiment with the antenna system (broken line) having no stub structure with respect to the directivity characteristic with respect to the coin wave. 51 shows reception sensitivity characteristics (solid line) when the horizontally polarized FM radio waves (88 MHz to 108 MHz) are received by the antenna system having the stub structure of the second embodiment, and when the antenna system having no stub structure is received. Indicates the reception sensitivity (dashed line) of. Fig. 52 is a diagram comparing the antenna system (solid line) of the second embodiment with the antenna system (broken line) having no stub structure with respect to the directivity characteristic for the radio wave. 53 shows reception sensitivity characteristics (solid line) when vertically polarized FM radio waves (76 MHz to 90 MHz) are received by the antenna system having the stub structure of the second embodiment, and when received by an antenna system having no stub structure. The reception sensitivity (dashed line) is displayed. FIG. 54 is a diagram comparing the antenna system (solid line) of the second embodiment with the antenna system (broken line) having no stub structure in terms of directing characteristics with respect to the coin wave.

49 to 54 show that the AM antenna wire for the copper stub structure does not affect the reception performance (reception sensitivity and directivity) of the FM radio waves.

Comparison with the first embodiment

55 shows reception sensitivity (solid line) when horizontally polarized FM radio waves (76 MHz to 90 MHz) are received by the antenna system of the second embodiment, and reception sensitivity (broken line) when received by the antenna system of the first embodiment. do. Fig. 56 shows the directivity (solid line) when the same FM radio wave is received by the antenna system of the second embodiment and the directivity (broken line) when it is received by the antenna system of the first embodiment.

54 and 55 show that the open stub structure of the second embodiment can ignore the influence of the antenna line 31 on the right glass, so that FM reception performance not affected by the AM antenna line can be obtained. Giving. The antenna system having the open stub structure of the second embodiment can be any antenna line as shown in FIG. 21, or can be replaced by, for example, a monopole antenna line or a loop antenna line. It is displayed. In addition, by adopting the open stub structure that the AM antenna line does not affect the FM reception performance, the FM radio wave received signal received by the AM antenna line 31 is fed to the feed point 16 via the connection line 14. In this case, a coil or the like for cutting off the FM signal, which has been required in the past, may be unnecessary.

AM reception performance

The following is a comparison of the reception sensitivity for AM propagation of the antenna system (or antenna system of the first embodiment) of the second embodiment with that of the conventional filler antenna. In particular, Table 1 and Table 2 show examples of using AV selection as the connection line 14, and Table 3 summarizes the AM reception sensitivity when the type of connection line is changed in various ways.

Table 1 shows the antenna system of the first and second embodiments using 1.5C cables of 75Ω from the antenna to the tuner.

From the above two tables, it can be seen that the AM antenna line 31 on the right glass surface connected via the antenna line 30 on the left glass surface and the AV line 14 functions as AM sensitivity correction. . In particular, according to Table 1 using a 1.5C cable, in the example of Table 2 using an average of about 4 dB, and a low-capacity cable, the sensitivity is improved by 3 dB on average. The magnitude of the contribution to the AM sensitivity improvement of the AM antenna line 31 on the right glass can be seen.

As apparent from Table 3, it is understood that the use of the AV line as the connecting line increases the sensitivity by about 2 dB on average compared with the use of the cognate cable. This is because when a coaxial cable is used, the stray capacitance in the cable acts as an ineffective capacity and results in a loss of sensitivity.

Here, the difference between the conventional glass antenna system of Japanese Patent Laid-Open No. 4-77005 and the glass antenna system of the second embodiment will be described. In the antenna system of Japanese Patent Laid-Open No. 4-77005, an FM antenna pattern and a phase adjusting conductor element are provided on a first glass surface of two glasses, and they are connected to a feed point on the first glass surface. On the other hand, the same FM receiving antenna pattern is formed on the other second glass surface, and the antenna pattern is connected to a feed point formed on the second glass surface. These two feed points are guided out of the glass and joined by the same connection line.

That is, the signals received by the antenna patterns on the two glass surfaces are synthesized, and the synthesized signals are delivered to the tuner.

Therefore, the AM receiving antenna system of the second embodiment (in particular, the antenna line 30 on the left glass for AM reception and the antenna line 31 on the right glass) and the FM receiving antenna system of Japanese Patent Laid-Open No. 4-77005. If you compare

(1): The antenna line 31 on the right side glass of the second embodiment is connected to the antenna line 30 via the connecting line 14 and joined, and is connected to one feed point 16. Antenna lines 30 and 31 as a whole are serial connection systems. On the other hand, in Japanese Patent Laid-Open No. 4-77005, each antenna line on two glass surfaces has a respective feeding point. Therefore, the antenna system of Japanese Patent Laid-Open No. 4-77005 is a parallel system as a whole.

(2): Japanese Patent Laid-Open Publication No. 4-77005, which is characterized by a parallel configuration, requires a wide-cut coil. However, in the antenna system of the second embodiment having the open stub structure, the AM antenna wire does not affect FM reception. Therefore, such a coil becomes unnecessary.

(3) In Japanese Patent Laid-Open Publication No. 4-77005, which cannot be used for coaxial cable-on, although the floating capacity of the coaxial cable acts as an ineffective capacity, in the second embodiment of the present invention which does not matter if an AV line is used, a coaxial cable is used. High sensitivity can be maintained by using an inexpensive and low floating AV line without using it.

Noise reduction

This is a problem that occurs when the antenna line is mounted on the side glass, and many signal lines extend on the side of the vehicle body, and when the cable of the signal line is close to the antenna line on the glass surface, it becomes a noise source.

In FIG. 19, the antenna system of the second embodiment distributes AM reception sensitivity by extending the AM reception antenna lines of the left and right side glass with respect to AM reception. This suppresses the reception sensitivity of the antenna lines 30 and 31 on the individual glass to be low. Therefore, the AM receiving antenna wire with reduced sensitivity can obtain the advantage that the sensitivity is low even for reception of noise.

In particular, since the left and right flashers rarely work at the same time, the flasher blinks only at the right or left side at some time. Accordingly, the AM received signal is synthesized to improve the sensitivity, but since the noise from the device which does not operate at the same time at the left and right is half, the absolute amount of the noise is reduced.

In addition, the principle of the second noise reduction means employed in the second embodiment will be described. 20 and 21, the distance from the glass perimeter of the antenna wire 30-3 on the left glass 10L is 30 mm, whereas the antenna line 31-3 on the right glass 10R ( The distance from the lowest end of each of 31-4) (31-5) to the edge of the glass is 80 mm. That is, the distance from the noise source in the antenna line on the right side glass 10R is taken larger than the distance from the noise source in the left side glass. In other words, the reception sensitivity to noise is relatively reduced in the right glass. In addition, on the left glass, an antenna line 30-3 in the horizontal direction is provided, whereas in the right glass, an AM antenna line extending in the horizontal direction is not provided in the lower glass part. This non-installation also helps to reduce noise reception sensitivity in the right glass.

FIG. 57 shows the result of comparing the second embodiment of the present invention, which employs a dispersion arrangement of the AM antenna lines 30 and 31 with the separation from the noise source, and the prior art (Examples 1 to 3).

In the conventional example 1 of FIG. 57, when the antenna system was constructed by dropping the AM antenna of normal sensitivity from the harness which is the noise source, the magnitude of the noise noise received from the harness was 6 dB, and the AM reception sensitivity at that time was 12 dB. . If the magnitude of the noise is 6 dB, it is within the allowable range. If the reception sensitivity is 12 dB, there is no hearing problem. However, when the AM antenna wire of the conventional example 1 was installed near the harness, as shown in the conventional example 2 of FIG. 57, the AM reception sensitivity was maintained at 12 dB, but the magnitude of the noise was increased to 12 dB, resulting in hearing loss. The problem was great.

However, in the second embodiment, the lower left antenna line 30 (-5 dB) is installed near the harness (30 mm from the edge of the glass as shown in FIG. 20), and the lower right antenna line 31 of the low sensitivity is similarly applied. (-8dB) is placed far away from the harness (80mm from the edge of the glass circumference, as shown in Fig. 21). For this reason, the AM reception sensitivity by the left antenna line 30 is 7 dB and the reception sensitivity by the right antenna line 31 is 4 dB. Therefore, the reception sensitivity of 11 dB is selected in the whole system, so there is no problem in practical use. In addition, since the magnitude of the ration noise received by the left antenna line 30 was 7 dB, and the magnitude of the ration noise received by the right antenna line 31 was 0 dB, the total was 7 dB, and this value was within the practically acceptable range.

<Effect of Second Embodiment>

In addition to the above effects ①-③ of the first embodiment,

(4) Since the open stub configuration is adopted, the antenna line 31 on the right glass does not affect the antenna line 20, and the design of a high performance glass antenna system is facilitated.

(5): Antenna lines 30 and 31 disposed on the left and right glass surfaces are connected in series, and as a result, the drop of the middle of the glass area is lower than that of the conventional parallel connection method in Japanese Patent Laid-Open No. 4-77005. Gets bigger

Therefore, the sensitivity equivalent to the conventional filler antenna can be obtained also for FM reception, and the one equivalent to the filler antenna can be obtained also for AM reception.

(6) By extending the AM receiving antenna lines 30 and the antenna lines 31 on the left and right glass surfaces, respectively, the reception sensitivity of the antenna lines can be lowered. For this reason, the amount which each antenna line takes noise is low.

(7): The noise reception level can be lowered by separating the antenna wire 31 from the harness largely on the right glass only, and the antenna wire 30 on the other left glass 10L is taken along the circumferential edge of the glass. By doing so, a function as an AM antenna line can be ensured. In other words, both noise reduction and AM sensitivity are achieved.

(8) The noise from the harness can be reduced by cutting the antenna line of the lowest side among the antenna lines on the right glass 10R. This is because the antenna line on the right glass acts as an assistant to the antenna line 30 of the left glass for AM reception, and therefore it is allowed to cut the antenna line of the lowest side.

<Effects Common to First and Second Embodiments>

In addition to the above ①-③, the following effects can be obtained as the effects common to the first and second embodiments described above.

I: As shown in FIG. 8, the reception function can be continued even if one is cut by duplexing the FM antenna line 20. FIG.

II: A branch line for AM antenna wires installed at the edges of glass, and monopole antenna wires are extended as shown in Fig. 8 (30-6) or 21 (31-4) to improve AM reception sensitivity. You can.

By separating the III: AM line from the harness, the influence from noise can be reduced.

<Variation>

The vehicle to which the present invention is to be applied is not limited to automobiles such as vans and wagons. In general, if the vehicle is equipped with glass, it applies to all vehicles.

In addition, the position of the glass to which the present invention is to be applied is not limited to the side glass of the rear magnet. In the principle of the present invention, it is applicable to any glass surface in one vehicle. For example, the glass antenna of the first embodiment is not limited to the glass of the rear magnet, but can be applied to the glass surface of the entire seat or, in some cases, to the rear glass surface. In addition, in the second embodiment, two or more pieces of glass may be applied to the glass antenna of the present invention. Further, the two or more glasses have many variations, such as the same side glass, such as one right (or left) glass close to the front magnet and one right (or left) glass close to the rear magnet. In other words, in the second embodiment, as long as the additional antenna line 31 for the low frequency band AM is different from the main antenna line 30 for the band, it may be anywhere in principle.

The present invention is not limited to the AM reception and the FM reception. The same applies to the reception of two radio waves, high and mid (or low).

The serial connection of the antenna lines using the AV line of the second embodiment is also applicable in principle to antenna lines provided on three or more glass surfaces.

As described above, according to the vehicle glass antenna of the present invention, a high performance vehicle glass antenna is proposed by combining antenna lines respectively provided on two glass surfaces of a vehicle, and by stub configuration and serial connection.

According to the design method of the present invention, since the stub structure and the serial connection are freed from the trouble of considering the influence of different frequency bands, it is possible to easily design a high performance glass antenna system.

1 is a diagram showing the configuration of an antenna system according to a first embodiment of the present invention.

2 is a diagram showing the effect of the length on reception sensitivity when the length of the AM antenna line is increased in the first embodiment.

3 is a diagram showing the influence of the length on reception sensitivity when the length of the AM antenna line is increased in the first embodiment.

4 is a diagram showing the influence of the length on reception sensitivity when the length of the AM antenna line is increased in the first embodiment.

5 is a diagram showing the effect of the length on reception sensitivity when the length of the AM antenna line is increased in the first embodiment.

FIG. 6 is a diagram showing the influence of the length on the reception sensitivity when the length of the AM antenna line is increased in the first embodiment.

FIG. 7 is a diagram showing a modification in which branch lines 30-6 are provided in the AM receiving antenna wire 30 of the first embodiment (or the second embodiment).

8 is a diagram showing the configuration when the antenna line 20 of the first embodiment (or the second embodiment) is doubled.

9 is a diagram illustrating the effect of redundancy of an FM antenna line.

10 is a diagram illustrating the effect of redundancy of an FM antenna line.

11 is a diagram illustrating an experimental result of the effect of redundancy of an FM antenna line.

12 is a diagram illustrating an experimental result of the effect of redundancy of an FM antenna line.

13 is a diagram illustrating an experimental result of the effect of the redundancy of the FM antenna line.

14 is a diagram illustrating an experimental result of the effect of redundancy of an FM antenna line.

15 is a diagram illustrating an experimental result of the effect of redundancy of an FM antenna line.

FIG. 16 is a diagram illustrating an experimental result of the effect of redundancy of FM antenna rays.

FIG. 17 is a diagram illustrating an experimental result of the effect of redundancy of an FM antenna line

18 is a diagram illustrating an experimental result of the effect of redundancy of an FM antenna line.

19 is a diagram for explaining the configuration of a second embodiment of the present invention.

20 is a diagram for explaining an antenna system on the left glass of the second embodiment.

21 is a view for explaining an antenna system on the right glass of the second embodiment.

22 is a view for explaining the VSWR characteristic when 1 = 20 cm in the second embodiment.

FIG. 23 is a view for explaining the VSWR characteristic when 1 = 40 cm in the second embodiment.

24 is a diagram for explaining the VSWR characteristics when 1 = 60 cm in the second embodiment.

25 is a view for explaining the VSWR characteristic when 1 = 80 cm in the second embodiment.

26 is a view for explaining the VSWR characteristic when 1 = 100 cm in the second embodiment.

FIG. 27 is a diagram for explaining the VSWR characteristic when 1 = 120 cm in the second embodiment.

28 is a view for explaining the VSWR characteristic when 1 = 140 cm in the second embodiment.

29 is a diagram for explaining the VSWR characteristic when 1 = 160 cm in the second embodiment.

30 is a view for explaining the VSWR characteristic when 1 = 180 cm in the second embodiment.

FIG. 31 is a diagram for explaining the VSWR characteristic when 1 = 200 cm in the second embodiment.

32 is a diagram for explaining the VSWR characteristic when 1 = 220 cm in the second embodiment.

33 is a view for explaining the VSWR characteristic when 1 = 235 cm in the second embodiment.

34 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 40 cm in the second embodiment.

35 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 60 cm in the second embodiment.

36 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 80 cm in the second embodiment.

37 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 100 cm in the second embodiment.

38 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 120 cm in the second embodiment.

FIG. 39 shows the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 140 cm in the second embodiment.

40 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 160 cm in the second embodiment.

41 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 180 cm in the second embodiment.

42 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 200 cm in the second embodiment.

43 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 220 cm in the second embodiment.

44 is a view showing the connection position between the left antenna wire 30 and the right antenna wire 31 when 1 = 235 cm in the second embodiment.

45 is a diagram for explaining the VSWR characteristic of the first embodiment.

46 is a diagram showing the reception sensitivity of the horizontal polarized wave FM radio wave reception between the second embodiment and the conventional filler antenna.

FIG. 47 is a diagram showing the directivity performance of horizontal polarization FM radio wave reception between the second embodiment and a conventional filler antenna. FIG.

48 is a diagram showing the reception sensitivity of the vertical polarization FM radio wave reception between the second embodiment and the conventional filler antenna.

FIG. 49 is a diagram for explaining the effect of stub reception on FM radio waves (horizontal polarization in the 76 to 88 MHz band) in the second embodiment.

FIG. 50 is a diagram for explaining the influence on the directivity of the stub for receiving FM radio waves (horizontal polarization in the 76-88 MHz band) in the second embodiment.

FIG. 51 is a diagram for explaining the effect of stub reception on FM radio waves (horizontal polarization in the 88 to 108 MHz band) in the second embodiment.

FIG. 52 is a diagram for explaining the influence on the directivity of the stub to receive FM waves (horizontal polarization in the 88-108 MHz band) in the second embodiment.

FIG. 53 is a diagram for explaining the influence of the stub on the FM propagation (vertical polarization in the 76-88 MHz band) in the second embodiment.

FIG. 54 is a diagram for explaining the influence on the directivity of the stub for receiving FM waves (vertical polarization in the 76 to 88 MHz band) in the second embodiment.

55 is a view showing the performance comparison between the installation and the right glass antenna in the second embodiment;

56 is a diagram showing the performance comparison between the installation and the installation of the right glass antenna according to the second embodiment.

57 is a diagram for explaining the noise reduction result in the second embodiment.

(10L). . . Left (left) glass (10R). . . Right (right) glass

(14). . . Connection line 15L (15R). . . Connection point

(16). . . Feed point 20, 30, 31. . . Antenna wire

Claims (15)

A method of designing antennas on first and second glass surfaces to receive radio waves in a first frequency band and in a second frequency band lower than the first frequency band, Determining the length of the first antenna wire and the position of the feed well, which extend substantially upward and downward on the first glass surface for receiving radio waves of the first frequency band; Determining a length and a termination position of a second antenna line so as to extend along an upper edge of the first glass surface from the feed point to receive radio waves of the second frequency band; Determining a position of the connection point such that the connection point on the second antenna line is a predetermined distance away from the feed point; And A length of a third antenna wire extending on the second glass surface and connected to the second antenna wire at the connection point, and having a high impedance between the second antenna wire and the third antenna wire with respect to the first frequency band; Determining to present; Design method of a vehicle glass antenna comprising a. In a glass antenna for a vehicle receiving radio waves of a first frequency band and a second frequency band lower than the first frequency band, A first antenna line extending over a first glass to be installed at a side of the vehicle to receive radio waves of the first frequency band and having a feed point on the first glass; A second antenna line extending along an edge of the first glass to receive radio waves of the second frequency band and having one end connected to the first antenna wire at a position near the feed point; A third antenna line extending over the second glass on the side opposite to the first glass in the left and right directions with respect to the first glass to receive radio waves of the second frequency band; And A connecting line for connecting the second antenna line and the third antenna line, wherein one end portion is connected to the third antenna line at a predetermined position on the second glass, and the other end portion is the first antenna line. A connecting line connected to the second antenna wire at a position apart from the feeding point on a glass surface; Vehicle antenna, characterized in that provided with. The method of claim 2, And the first antenna line extends downward from an approximately center position in the width direction of the first glass surface. The method of claim 2, The second antenna wire is formed in a loop shape along the edge of the first glass, and is terminated without returning to the feed point. The method of claim 4, wherein And the second antenna line has a branch line at an intermediate portion thereof. The method of claim 2, And wherein the third antenna line has an additional line extending along an approximately horizontal edge above the second glass and at least two additional lines extending along an approximately upper and lower edge of the second glass. Yuri antenna. The method of claim 6, The first glass and the second glass has a substantially rectangular shape, The second antenna line has an additional line extending along a substantially horizontal edge below the first glass, The third antenna line has an additional line extending along an approximately upper and lower edge of the second glass, The distance from the lower end of the second glass to the additional line of the third antenna line is set longer than the distance from the lower end of the first glass to the additional line of the second antenna line. antenna. In a glass antenna for a vehicle receiving radio waves of a first frequency band and a second frequency band lower than the first frequency band, A first antenna line extending over the first glass of the vehicle to receive radio waves of the first frequency band and having an effective feeding point installed on the first glass; A second antenna wire connected to the first antenna wire to receive radio waves of the second frequency band and extending along a edge of the first glass in a predetermined length; A third antenna line extending on a second glass different from the first glass to receive radio waves of the second frequency band; And A connecting line for connecting the second antenna wire and the third antenna wire, one end of which is connected to the third antenna wire at a predetermined first connection position on the second glass, and the other end of which is connected to the third antenna wire. A connection line connected to the second antenna line at a predetermined second connection position spaced apart from the feed point on the first glass surface; Vehicle antenna, characterized in that provided with. The method of claim 8, The first glass is provided on the side of the vehicle, the second glass is a vehicle antenna, characterized in that provided on the side opposite to the left and right direction of the vehicle with respect to the first glass. The method of claim 8, And the first frequency band is an FM frequency band, and the second frequency band is an AM frequency band. The method of claim 8, And the first antenna line extends downward from an approximately center position in the width direction of the first glass. The method of claim 8, The second antenna wire is formed in a loop shape along an edge of the first glass, and is terminated without returning to the feed point. The method of claim 12, And the second antenna line has a branch line at an intermediate portion thereof. The method of claim 8, And wherein the third antenna line has an additional line extending along an approximately horizontal edge above the second glass and at least two additional lines extending along an approximately upper and lower edge of the second glass. Yuri antenna. The method of claim 14, The first glass and the second glass has a substantially rectangular shape, The second antenna line has an additional line extending along a roughly crystallographic edge below the first glass, The third antenna line has an additional line extending along an approximately upper and lower edge of the second glass, The distance from the lower end of the second glass to the additional line of the third antenna line is set longer than the distance from the lower end of the first glass to the additional line of the second antenna line. antenna.